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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2022-08-09 12:54:25 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-11-24 13:31:46 +0100 |
| commit | 7af82ff90a2b0690c2c45818fcce4c4ac3b187f3 (patch) | |
| tree | 9341d7604ef37c7ffb553beb221507e507009e85 /arch/powerpc/include/asm | |
| parent | powerpc/pseries: Fix formatting to make code look more beautiful (diff) | |
| download | linux-7af82ff90a2b0690c2c45818fcce4c4ac3b187f3.tar.xz linux-7af82ff90a2b0690c2c45818fcce4c4ac3b187f3.zip | |
powerpc/ftrace: Ignore weak functions
Extend commit b39181f7c6907d ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to
avoid adding weak function") to ppc32 and ppc64 -mprofile-kernel by
defining FTRACE_MCOUNT_MAX_OFFSET.
For ppc64 -mprofile-kernel ABI, we can have two instructions at function
entry for TOC setup followed by 'mflr r0' and 'bl _mcount'. So, the
mcount location is at most the 4th instruction in a function. For ppc32,
mcount location is always the 3rd instruction in a function, preceded by
'mflr r0' and 'stw r0,4(r1)'.
With this patch, and with ppc64le_guest_defconfig and some ftrace/bpf
config items enabled:
# grep __ftrace_invalid_address available_filter_functions | wc -l
79
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220809105425.424045-1-naveen.n.rao@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm')
| -rw-r--r-- | arch/powerpc/include/asm/ftrace.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index 3cee7115441b..ade406dc6504 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -10,6 +10,13 @@ #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR +/* Ignore unused weak functions which will have larger offsets */ +#ifdef CONFIG_MPROFILE_KERNEL +#define FTRACE_MCOUNT_MAX_OFFSET 12 +#elif defined(CONFIG_PPC32) +#define FTRACE_MCOUNT_MAX_OFFSET 8 +#endif + #ifndef __ASSEMBLY__ extern void _mcount(void); |